War or peace? You can’t have it both ways, despite what Dostoyevsky wrote, but it’s difficult to know which side to root for in this 17th-century tale of clashing Asian nations. (And no fair Googling “events of 1636” to see how it all turned out.)

On the one hand, we have Injo (Hae-il Park), king of Josean (modern-day Korea), holed up in a mountain fortress under siege by the forces of the Qing Empire (China). On the other, General Ingguldai, leading the siege and awaiting the arrival of his own emperor.

Somewhere in the middle, possibly a traitor, maybe a patriot, certainly a pragmatist, is Choi (Korean superstar Byung-hun Lee). As a courtier, he has the ear of the king; as a messenger, valuable information about the invaders. But his travels between camps has many certain he’s a traitor, and calling for his head.

Peace would spare the lives of countless soldiers and citizens, already facing starvation as the winter siege continues. But war spells exciting computer-generated mayhem, even if director Dong-hyuk Hwang isn’t exactly known for that in previous light fare like Miss Granny.

Without giving too much away, there’s something for everyone here. Politicians plot and debate before the king; skirmishes take place in the shadow of the mountain redoubt; and Choi walks a thin line between violence and appeasement, occasionally stumbling to one side or the other. (In an early scene, he slays a boatman after the man says he’ll help the enemy cross his river.) At more than two and a quarter hours, the subtitled Fortress is a little long, but still succeeds as a thinking person’s war movie.